Rather than being intended for wear by canine or feline fire operatives plunging into burning buildings to rescue people in the style of Lassie or similar - compressed-air kit would of course be more normal in such a role - the masks are meant for therapeutic use. A man's best friend, or alternatively a freeloading moggy, having been plucked from the fiery jaws of death by a regular helmeted hero, might find its lungs messed up by smoke and unequal to the task of sustaining life.

But placed on oxygen the lungs have an easier time and such a furry casualty would then have a greatly improved chance of survival.

There would be no obvious application in the case of cats stuck up trees, however.

Other uses for pet oxygen-breathing equipment have lately been found: we at the Reg have lately reported in passing on the case of the current world record holder for highest man+dog tandem freefall parachute jump, "Cara", who has jumped from such heights as to require oxygen. Cara's human henchman, Mike Forsythe, works as a canine parachuting instructor for military and search-and-rescue units around the world.

It's well known, of course, that America is one of the few nations to have parachute firemen: so perhaps the deployment of doggy oxygen masks by their ground-bound colleagues is a sign of things to come.